Aqueous polymer dispersion

Abstract

The present invention relates generally to an aqueous polymer dispersion and a coating composition made thereof, especially to a “green” antibacterial polymer dispersion with improved color stability property upon exposure to heat and/or light, and the coating composition made thereof.

The invention claimed is: 
     
       1. An aqueous polymer dispersion comprising:
 a) a polymer comprising, as polymerized units, from 0.1% to 10% by dry weight percentage based on the dry weight of the polymer dispersion, at least one acetoacetoxy or acetoacetamide group containing monomer; 
 b) 0.001% to 0.15% by dry weight based on the dry weight of the polymer dispersion, of at least one metal ion selected from copper, silver, gold, tin, and zinc; and 
 c) an amino acid, being present in a mole ratio of amino acid to acetoacetoxy or acetoacetamide group containing monomer of from 0.9:1 to 5:1. 
 
     
     
       2. The aqueous polymer dispersion according to  claim 1  wherein the polymer comprises an acetoacetoxy group containing monomer selected from the group consisting of acetoacetoxyethyl(meth)acrylate, acetoacetoxypropyl (meth)acrylate, acetoacetoxybutyl (meth)acrylate, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, and combinations thereof. 
     
     
       3. The aqueous polymer dispersion according to  claim 1  wherein the polymer comprises an acetoacetamide group containing monomer having the formula as follows: 
       
         
           
           
               
               
           
         
         wherein R 6  is either H or methyl. 
       
     
     
       4. The aqueous polymer dispersion according to  claim 1  wherein the polymer comprises, as polymerized units, at least one nonionic monomer. 
     
     
       5. The aqueous polymer dispersion according to  claim 1  wherein the polymer comprises, as polymerized units, at least one ionic monomer. 
     
     
       6. The aqueous polymer dispersion according to  claim 1  wherein the metal ion is silver ion. 
     
     
       7. The aqueous polymer dispersion according to  claim 1  wherein the amino acid is glycine, 3-aminopropanoic acid, 4-aminobutyric acid, or a mixture thereof. 
     
     
       8. A coating composition comprising the aqueous polymer dispersion according to  claim 1 . 
     
     
       9. The aqueous polymer dispersion according to  claim 1 , wherein the amino acid is glycine, 3-aminopropanoic acid, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminocaproic acid, 7-aminohepanoic acid, serine, threonine, tyrosine, beta-alanine, or a combination comprising at least one of the foregoing.